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The Evolution of Tunnel Boring Machines

construction-physics.com

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Re: The Evolution of Tunnel Boring Machines

#111

Post by runarberg »

teruakohatu wrote: post #74
runarberg wrote: post #60

Earlier quoted context omitted.

I don’t buy it. 25% of workers is a lot of workers for a megaproject of this scale. This would either have to be a single devastating week, in which case they would learn about it really quickly and would probably still be the collective memory, or O'Rourke Engineering Construction Company willfully allowed their workers to die out of mysterious causes and opted not to investigate. The latter is actually more likely…

I can believe it, and I can believe it is still in the collective memory of the relevant unions since it is apparently partly the reason for their existence. From NY Time Archive: [1] > In 1890, 68 sandhogs died as they bored a gas tunnel under Welfare Island, now Roosevelt Island. A Manhattan coroner estimated that at least 50 sandhogs died in the first five months of 1906 in the construction of Pennsylvania Railroa…

25% of underground workers is a far more reasonable number, and I can actually believe that. Don’t get me wrong, companies during the guilded age had no respect for their workers, and if they had to choose between worker’s lives or company profit, they choose profit 100% of the time.

I just think that even during this horrible time period, you still couldn’t get away with loosing 25% of your workers while still getting the job done.

Re: The Evolution of Tunnel Boring Machines

#112

Post by digging »

jcims wrote: post #55
digging wrote: post #25

Earlier quoted context omitted.

A common but misguided desire.

Of course, but it would be fun to design and build. And since it will obviously never happen it seems pretty harmless to think about?

As an engineering challenge, yeah, the machine itself is super interesting. But "more road" isn't the answer to road congestion so it's a machine without a purpose (unless the purpose is propping up the oil & auto industries?).

Re: The Evolution of Tunnel Boring Machines

#113

Post by s1artibartfast »

runarberg wrote: post #110
s1artibartfast wrote: post #108

Earlier quoted context omitted.

I think this further supports the point about the unfathomable cheapness of life before the 1900's.

I would put that date a little closer in time actually. And I actually have a precise date. I think that labor was unfathomably cheap until July 6th 1935, when the National Labor Relation act was enacted. Both the tunnel and the canal (under USA supervision) didn’t start construction until 1904. But that said, by far the majority of the deaths during the construction of the Panama Canal were under French supervision,…

It has never been practical to simply disregard the practical financial and labor implications of human life and get the job done. If all your workers starve, they wont shovel. If there are no replacements, work stops.

I think what is interesting is the expansion from purely logistical/financial implications to include other considerations.

These other considerations including legal ones, as labor laws were passed, civil liability law developed, social sentiments changed, and welfare increased so that people didnt have to choose be 50% chance of death or starvation.

Re: The Evolution of Tunnel Boring Machines

#114

Post by lstodd »

_8j50 wrote: post #104
krisoft wrote: post #91

Earlier quoted context omitted.

> There are lakes such as superior in michigan or even mammoth lakes in cali. Yes. Lakes as a concept exist. There are many examples. What are you proposing? > I also wondered why not instead of recycling desalinated water after use, have it fill up a lake. Okay. Just for the aesthetic value? Or to evaporate it? Let me get it straight: you are proposing to pipe the output of wastewater treatment plants to an open bas…

> Yes. Lakes as a concept exist. There are many examples. What are you proposing? Rivers from the lakes to unpopulated arid or drought striken parts of the country. > Okay. Just for the aesthetic value? Or to evaporate it? To use it to create a fresh water source that will feed a river. The evaporation I perhaps wrongly assumed will become rain somewhere relatively near by? But even without that, my assumption is mos…

Most of whatever is now dry and unpopulated, including in the US is so because moisture is being pumped out of there by the atmosphere and sun. Not because someone forgot to drive some water there.

It is being moved out of there in such amounts that no economically possible diversion of water flow can overcome this. Cf the crazy and eventually buried USSR project of diverting north-flowing rivers water to the Kazakhstan from 80s.

That could not work even in theory, where the talk was about thousands of cubic meter per second and you suggest that some toilets can make this work. That is just not possible. Maybe if the climate actually changes, some of those lands will become good enough for agricultural use. But not now.

Re: The Evolution of Tunnel Boring Machines

#115

Post by Retric »

s1artibartfast wrote: post #107
benj111 wrote: post #93

Earlier quoted context omitted.

>as they were healthier in general Source? Survivorship bias? How many people do you know who've had polio? Small pox? Rubella? Mumps? Died from a bacterial infection? Blinded from cataracts?

You failed to quote the critical part of the sentence. >They also didn't have to worry about the same healthcare costs, as they were healthier in general, and the options were far fewer when sick. People were less obese, spent less time battling disease, and died younger. It's somewhat similar to survivorship bias, but it is a real effect. You can look up population incidence and prevelance rates for diabetes, obesit…

Polio etc survivors may have been less obese but they didn’t spend less time battling disease.

Often someone would be dealing with the consequences of childhood illnesses or injuries for decades.

Re: The Evolution of Tunnel Boring Machines

#116

Post by s1artibartfast »

Retric wrote: post #115
s1artibartfast wrote: post #107

Earlier quoted context omitted.

You failed to quote the critical part of the sentence. >They also didn't have to worry about the same healthcare costs, as they were healthier in general, and the options were far fewer when sick. People were less obese, spent less time battling disease, and died younger. It's somewhat similar to survivorship bias, but it is a real effect. You can look up population incidence and prevelance rates for diabetes, obesit…

Polio etc survivors may have been less obese but they didn’t spend less time battling disease. Often someone would be dealing with the consequences of childhood illnesses or injuries for decades.

Indeed, but I am talking about the sum of all disease.

Polio is a good example of the opposite, because polio today is effectively zero. Most other types of disease trend the other way with much more significant margins.

Polio lead to some level of paralysis in somewhere between 0.5-0.2% percent of people, many of whom died and needed no further healthcare.

Today, a far larger percent of Americans have lost the ability to walk due to obesity and diabetes.

Re: The Evolution of Tunnel Boring Machines

#117

Post by ggm »

jtriangle wrote: post #86
ggm wrote: post #35

The projection for boring company is interesting at least. They seem to argue most of the "wins" are procedural, and relate to business practices, paperwork and general business efficiency, the "we can do 1km a day" claims not withstanding (they don't claim this. But, it is definitely an out-there claim of their speed) -The reality of the equipment and process they use is still an advance on most, but it's more norma…

We had nuclear tbm's in the early 70's, but nobody thought to develop them further than a few prototypes. They worked though, and were very fast for their time, still quite fast even by today's standards.

We didn't have them we had non nuclear test instances and patents, and nobody ever scaled it up to use nuclear power.

Re: The Evolution of Tunnel Boring Machines

#118

Post by dredmorbius »

s1artibartfast wrote: post #108
dredmorbius wrote: post #84

Earlier quoted context omitted.

Deaths during construction of the Panama Canal were overwhelmingly from tropical diseases, notably yellow fever and malaria: https://en.wikipedia.org/wiki/Health_measures_during_the_con... > The transmission of yellow fever by mosquitos was established by Maj. Walter Reed, US Army, the physician for whom Walter Reed Hospital is named: https://en.wikipedia.org/wiki/Walter_Reed > The shear lethality of tropical disease…

I think this further supports the point about the unfathomable cheapness of life before the 1900's.

There's a key distinction that I'd like to point out.

Operational safety based risks, such as experienced in direct earthworks, blasting, transport, etc., disproportionately affect front-line workers.

Infectious disease based risks are largely indiscriminate between front-line and managerial staff. That is, unskilled labourers and administrative, clerical, officer, etc., staff all largely face a similar threat against vector-transmitted diseases. The only option for the latter is to avoid the location or posting entirely.

That may be a subtle shading, and points about the US NRL made by runarberg are well taken, but again, it seems significant.

Note that tropical diseases were an issue across the Panamanian isthmus for travelers and transport workers (sailors, teamsters, railroad) who traversed the region even before the canal was built, as an overland leg in the East-to-West-coast route which avoided both the time and perils of going 'round the Cape, encircling all of South America.

A railroad was opened across the isthmus in 1855. That effort cost 5-10k workers' lives itself.

https://en.wikipedia.org/wiki/Panama_Canal_Railway>

And, somewhat supporting your viewpoint, Adam Smith describes the career duration of workers at his time (~1750--1775): "A carpenter in London, and in some other places, is not supposed to last in his utmost vigor above eight years."

-- Adam Smith, Wealth of Nations, Book 1, Chapter 8, "Of the Wages of Labour"

https://en.wikisource.org/wiki/The_Wealth_of_Nations/Book_I/...>

Similarly, prior to the development of modern sanitation and hygiene (fresh water supplies, sewerage systems, regular bathing, handwashing), cities were net population sinks and relied on in-migration from surrounding countryside (often driven by limited employment and income potential there) in order to simply maintain population levels. Infectious disease deaths within cities could top 50 thousand per year in 19th century London and New York, out of populations of 1 million or fewer.

Re: The Evolution of Tunnel Boring Machines

#119

Post by s1artibartfast »

dredmorbius wrote: post #118
s1artibartfast wrote: post #108

Earlier quoted context omitted.

I think this further supports the point about the unfathomable cheapness of life before the 1900's.

There's a key distinction that I'd like to point out. Operational safety based risks, such as experienced in direct earthworks, blasting, transport, etc., disproportionately affect front-line workers. Infectious disease based risks are largely indiscriminate between front-line and managerial staff. That is, unskilled labourers and administrative, clerical, officer, etc., staff all largely face a similar threat agains…

>cities were net population sinks and relied on in-migration from surrounding countryside.

Now that's interesting. I consider myself dark realist when it comes to history but I haven't read that. I'm guessing it must be constrained to some pretty specific circumstances and period in time.

Re: The Evolution of Tunnel Boring Machines

#120

Post by dredmorbius »

s1artibartfast wrote: post #119
dredmorbius wrote: post #118

Earlier quoted context omitted.

There's a key distinction that I'd like to point out. Operational safety based risks, such as experienced in direct earthworks, blasting, transport, etc., disproportionately affect front-line workers. Infectious disease based risks are largely indiscriminate between front-line and managerial staff. That is, unskilled labourers and administrative, clerical, officer, etc., staff all largely face a similar threat agains…

>cities were net population sinks and relied on in-migration from surrounding countryside. Now that's interesting. I consider myself dark realist when it comes to history but I haven't read that. I'm guessing it must be constrained to some pretty specific circumstances and period in time.

Gregory Clark cites this fact in his book A Farewell to Alms:

https://archive.org/details/farewelltoalmsbr00clar/page/92/m...>

Specifically, that situation prevailed from the 16th through 19th centuries. That's a brief period from a geological standpoint I suppose...

https://www.worldcat.org/title/farewell-to-alms-a-brief-econ...>

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